A similar position is shown in Dia 4. Correct play for White is as
in Dia 5, where White 1 threatens to capture three black stones. Going
back to Dia 4, because white A is sente the white hane at the marked
stone is a play worth seven points, (assume for counting purposes that a
player will always achieve his own sente moves) - seven and not six
because if Black were to play this move, B will eventually be his sente
forcing White to connect at C.

If Black wants to take away White's sente of A after the marked
stone, then his best move locally is to play A himself. When the dame
are filled Black will then have to go back and take a liberty from the
three white stones. If you do the sum, you will find that a black play
at A saves three points, thus white at the marked stone in Dia 4 is
worth either seven points in gote or four in sente. Usually Black will
prefer to let him have the seven in order to play elsewhere (on the
basis that elsewhere is worth about seven points at the time when White
should play at the marked stone.)

This article is from the
British Go Journal
Issue 56[1]
which is one of a series[2] of back issues now available on the web.

Last updated Thu May 04 2017. If you have any comments, please email the webmaster on web-master AT britgo DOT org.